Display device and method of fabricating the same

ABSTRACT

A display device includes a display panel including a display area and a non-display area surrounding the display area, and a metal wiring layer disposed on at least a portion of the non-display area, an encapsulation substrate disposed on the display panel, a sealing member which is disposed between the display panel and the encapsulation substrate and bonds the display panel to the encapsulation substrate and a first fusion region provided in at least a partial region between the sealing member and the encapsulation substrate, where the first fusion region has no physical boundary, and where at least a portion of the sealing member is disposed on the metal wiring layer in the non-display area, and the first fusion region is separated from the metal wiring layer while overlapping the metal wiring layer in a thickness direction.

This application claims priority to Korean Patent Application No.10-2020-0004806, filed on Jan. 14, 2020, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND 1. Field

Embodiments of the invention relate to a display device and a method offabricating the same.

2. Description of the Related Art

An importance of display devices has steadily increased with adevelopment of multimedia technology. Accordingly, various types ofdisplay devices such as an organic light emitting display, a liquidcrystal display (“LCD”) and the like have been used.

A display device displays an image, and includes a display panel, suchas an organic light emitting display panel or an LCD panel. Amongdisplay panels, a light emitting display panel may include a lightemitting element. Examples of a light emitting diode (“LED”) include anorganic light emitting diode (“OLED”) using an organic material as afluorescent material, and an inorganic LED using an inorganic materialas a fluorescent material.

SUMMARY

Embodiments of the invention provide a display device capable ofimproving a bonding force of a sealing member for bonding a displaypanel and an encapsulation substrate to each other, and a method offabricating the same.

However, the invention is not restricted to the one set forth herein.The above and other features of the invention will become more apparentto one of ordinary skill in the art to which the invention pertains byreferencing the detailed description of the invention given below.

A display device in an embodiment includes a sealing member disposedbetween a display panel and an encapsulation substrate, and a fusionregion provided at least between the sealing member and theencapsulation substrate and having no physical boundary. The sealingmember is disposed to partially overlap a metal wiring layer provided ina non-display area of a display panel, and the fusion region isseparated from the metal wiring layer while overlapping the metal wiringlayer in a thickness direction. The sealing member is in direct contactwith the display panel and the encapsulation substrate to bond them toeach other, and at the same time, a fusion region further improves abonding force with the encapsulation substrate.

Since the display device in the embodiment includes the fusion regionprovided by fusing materials of the sealing member and the encapsulationsubstrate or the display panel at a boundary between the sealing memberand the encapsulation substrate or the display panel, durability of thedisplay device against external impact may be improved.

The effects of the invention are not limited to the aforementionedeffects, and various other effects are included in the specification.

An embodiment of the invention provides a display device including adisplay panel including a display area and a non-display areasurrounding the display area, and a metal wiring layer disposed on atleast a portion of the non-display area, an encapsulation substratedisposed on the display panel, a sealing member which is disposedbetween the display panel and the encapsulation substrate and bonds thedisplay panel to the encapsulation substrate and a first fusion regionprovided in at least a partial region between the sealing member and theencapsulation substrate, where the first fusion region has no physicalboundary, and where at least a portion of the sealing member is disposedon the metal wiring layer in the non-display area, and the first fusionregion is separated from the metal wiring layer while overlapping themetal wiring layer in a thickness direction.

In an embodiment, the first fusion region may be provided by mixing amaterial of the sealing member with a material of the encapsulationsubstrate.

In an embodiment, a height of the first fusion region may be greaterthan a thickness of the sealing member.

In an embodiment, the first fusion region may include a first portionoverlapping the sealing member and a second portion overlapping theencapsulation substrate, and where a maximum value of a width of thefirst portion may be greater than a maximum value of a width of thesecond portion.

In an embodiment, the sealing member may form a first boundary surfacewhere at least a portion of a lower surface of the sealing member is indirect contact with the metal wiring layer, and the first boundarysurface may have a physical boundary with the metal wiring layer.

In an embodiment, the sealing member may form a second boundary surfacewhere at least a portion of an upper surface of the sealing member is indirect contact with the encapsulation substrate, and the second boundarysurface may have a physical boundary with the encapsulation substrate,and where a physical boundary may do not exist in a portion where thefirst fusion region is provided on an extension line of the secondboundary surface.

In an embodiment, the first fusion region may include a third boundarysurface between the first portion and the sealing member and a fourthboundary surface between the second portion and the encapsulationsubstrate.

In an embodiment, a thickness of the sealing member may range from about4.5 micrometers (μm) to about 6 μm, and a height of the first portionmay range from about 2 μm to about 4 μm.

In an embodiment, a plurality of first fusion region is provided betweenthe sealing member and the encapsulation substrate, and a width of thefirst fusion region may be smaller than an interval between theplurality of first fusion regions.

In an embodiment, a maximum value of the width of the first fusionregion may range from about 8 μm to about 12 μm, and a maximum value ofa height of the first fusion region may range from about 8 μm to about12 μm.

In an embodiment, the interval between the plurality of first fusionregions may range from about 50 μm to about 100 μm.

In an embodiment, the display panel may further include an insulatinglayer disposed under the metal wiring layer, and where at least aportion of a lower surface of the sealing member may be in directcontact with the insulating layer.

In an embodiment, the display device may further include a second fusionregion provided between the sealing member and the insulating layer ofthe display panel, and the second fusion region may have no physicalboundary, where the second fusion region may be separated from theencapsulation substrate.

In an embodiment, the second fusion region may include a third portionoverlapping the sealing member and a fourth portion overlapping thedisplay panel, and where a maximum value of a width of the third portionmay be greater than a maximum value of a width of the fourth portion.

In an embodiment, the sealing member may be in direct contact with theinsulating layer of the display panel and includes a fifth boundarysurface where a physical boundary exists, and where a physical boundarymay do not exist in a portion where the second fusion region is providedon an extension line of the fifth boundary surface.

Another embodiment of the invention provides a display device includinga first substrate including a plurality of light emitting elements, thefirst substrate including a display area in which the plurality of lightemitting elements is disposed and a non-display area surrounding thedisplay area, a second substrate disposed on the first substrate, ametal wiring layer disposed in the non-display area of the firstsubstrate, a sealing member which is disposed between the firstsubstrate and the second substrate, overlaps the metal wiring layer andsurrounds the display area in the non-display area and a fusion regionprovided between the second substrate and the sealing member, thesealing member including a first extension portion extending in a firstdirection along the non-display area, a second extension portionextending in a second direction intersecting the first direction, and afirst corner portion connected to the first extension portion and thesecond extension portion, the first corner portion having a curvature,where the fusion region has no physical boundary, and where the fusionregion is provided at least in the first corner portion of the sealingmember.

In an embodiment, the fusion region may be also disposed in the firstextension portion and the second extension portion of the sealingmember, and where a plurality of fusion regions may be spaced apart fromeach other in the first direction and the second direction.

In an embodiment, the fusion region may form a closed curve and surroundthe display area along the sealing member.

In an embodiment, a trench portion in which at least one of side surfaceis recessed inward may be defined in the first substrate and the secondsubstrate, and where the sealing member may be disposed along an outersurface of the trench portion, and the fusion region is provided in thesealing member disposed corresponding to the outer surface of the trenchportion.

An embodiment of the invention provides a method of fabricating adisplay device, the method including preparing a first substrateincluding a display area and a non-display area and a second substratefacing the first substrate, bonding the first substrate to the secondsubstrate via a sealing member and irradiating an intense light to thesealing member to form a fusion region having no physical boundarybetween the second substrate and the sealing member.

In an embodiment, a focal point of the intense light may be set to beseparated from an upper surface of the second substrate, and aseparation distance between the focal point of the intense light and theupper surface of the second substrate may range from about 0.1 μm toabout 200 μm.

In an embodiment, the intense light may be irradiated at a frequency ofabout 1 kilohertz (kHz) to about 10 MHz for about 10 femtoseconds (fs)to about 50 picoseconds (ps).

In an embodiment, the fusion region may be disposed over the sealingmember and the second substrate and separated from the first substrate.

In an embodiment, the bonding the first substrate to the secondsubstrate may include filling frit crystals between the first substrateand the second substrate, and sintering and melting the frit crystals toform the sealing member.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other embodiments and features of the invention willbecome more apparent by describing in detail embodiments thereof withreference to the attached drawings, in which:

FIG. 1 is a schematic perspective view of an embodiment of a displaydevice;

FIG. 2 is a plan view of an embodiment of a display device;

FIG. 3 is a schematic side view of an embodiment of a display device;

FIG. 4 is a schematic plan view of a display panel;

FIG. 5 is a cross-sectional view illustrating one pixel of FIG. 4;

FIG. 6 is a schematic plan view illustrating an embodiment of a displaydevice having a sealing member disposed therein;

FIG. 7 is a cross-sectional view taken along line I-I′ of FIG. 6;

FIG. 8 is a cross-sectional view taken along line II-II′ of FIG. 6;

FIG. 9 is an enlarged view of portion A of FIG. 7;

FIG. 10 is a schematic plan view illustrating an embodiment of thearrangement of fusion regions provided in a sealing member of a displaydevice;

FIG. 11 is a cross-sectional view taken along line III-III′ of FIG. 10;

FIG. 12 is a flowchart showing an embodiment of a method for fabricatinga display device;

FIGS. 13 to 16 are cross-sectional views illustrating a process offabricating a display device;

FIG. 17 is a cross-sectional view illustrating a portion of a displaydevice;

FIG. 18 is a cross-sectional view partially illustrating a process offabricating the display device of FIG. 17;

FIGS. 19 to 21 are schematic plan views illustrating the arrangement offusion regions provided in a sealing member of a display deviceaccording to other embodiments;

FIG. 22 is a schematic plan view illustrating another embodiment of thearrangement of fusion regions provided in a sealing member of a displaydevice;

FIG. 23 is an enlarged schematic view of a portion SDA1 of FIG. 10;

FIG. 24 is an enlarged schematic view of a portion SDA2 of FIG. 10;

FIG. 25 is a cross-sectional view taken along line IV-IV′ of FIG. 23;

FIG. 26 is a cross-sectional view illustrating another embodiment of aportion of a display device; and

FIG. 27 is a cross-sectional view partially illustrating a process offabricating the display device of FIG. 26.

DETAILED DESCRIPTION

Embodiments of the invention will now be described more fullyhereinafter with reference to the accompanying drawings, in whichpreferred embodiments of the invention are shown. This invention may,however, be embodied in different forms and should not be construed aslimited to the embodiments set forth herein. Rather, these embodimentsare provided so that this invention will be thorough and complete, andwill filly convey the scope of the invention to those skilled in theart.

It will also be understood that when a layer is referred to as being“on” another layer or substrate, it may be directly on the other layeror substrate, or intervening layers may also be present. The samereference numbers indicate the same components throughout thespecification.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another element. For instance, a first elementdiscussed below could be termed a second element without departing fromthe teachings of the invention. Similarly, the second element could alsobe termed the first element.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It will be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. In anembodiment, when the device in one of the figures is turned over,elements described as being on the “lower” side of other elements wouldthen be oriented on “upper” sides of the other elements. The exemplaryterm “lower,” can therefore, encompasses both an orientation of “lower”and “upper,” depending on the particular orientation of the figure.Similarly, when the device in one of the figures is turned over,elements described as “below” or “beneath” other elements would then beoriented “above” the other elements. The exemplary terms “below” or“beneath” can, therefore, encompass both an orientation of above andbelow.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and theinvention, and will not be interpreted in an idealized or overly formalsense unless expressly so defined herein.

Embodiments are described herein with reference to cross sectionillustrations that are schematic illustrations of idealized embodiments.As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments described herein should not be construed aslimited to the particular shapes of regions as illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. In an embodiment, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the claims.

Hereinafter, embodiments of the invention will be described withreference to the accompanying drawings.

FIG. 1 is a schematic perspective view of an embodiment of a displaydevice. FIG. 2 is a plan view of an embodiment of a display device. FIG.3 is a schematic side view of an embodiment of a display device. In FIG.3, only a display panel 100 and an encapsulation substrate 500 areillustrated without showing a display circuit board 300 of a displaydevice 10.

In the specification, a first direction DR1 may be a direction parallelto a short side of the display device 10 in a plan view, for example, ahorizontal direction of the display device 10. A second direction DR2may be a direction parallel to a long side of the display device 10 in aplan view, for example, a vertical direction of the display device 10. Athird direction DR3 may be a thickness direction of the display device10. In addition, the first direction DR1 may be a rightward directionwhen the display device 10 is viewed from the third direction DR3, andan opposite direction of the first direction DR1 may be a leftwarddirection. The second direction DR2 may be an upward direction when thedisplay device 10 is viewed from the third direction DR3, and anopposite direction of the second direction DR2 may be a downwarddirection. The third direction DR3 may be an upward direction, and anopposite direction of the third direction DR3 may be a downwarddirection.

Referring to FIGS. 1 to 3, the display device 10 may be applied to avariety of electronic apparatuses, i.e., small and medium electronicdevices such as a tablet personal computer (“PC”), a smartphone, a carnavigation unit, a camera, a center information display (“CID”) providedin a vehicle, a wristwatch-type electronic device, a personal digitalassistant (“PDA”), a portable multimedia player (“PMP”) and a gameconsole, and medium and large electronic devices such as a television,an external billboard, a monitor, a personal computer and a laptopcomputer. These are merely suggested as examples, but the display device10 may also be applied to other electronic devices without departingfrom the scope of the invention.

The display device 10 may be a light emitting display device such as anorganic light emitting display using an organic light emitting diode(“OLED”), a quantum dot light emitting display including a quantum dotlight emitting layer, an inorganic light emitting display including aninorganic semiconductor, and a micro light emitting display using amicro light emitting diode (“LED”). In the following description, it isassumed that the display device 10 is an organic light emitting displaydevice, but the invention is not limited thereto.

The display device 10 includes the display panel 100 (or a firstsubstrate), a display driver 200, the display circuit board 300, theencapsulation substrate 500 (or a second substrate), and a sealingmember 700.

The display panel 100 may be provided in a quadrangular shape (e.g.,rectangular shape), in a plan view, including short sides in the firstdirection DR1 and long sides in the second direction DR2 intersectingthe first direction DR1. The corner where the short side in the firstdirection DR1 and the long side in the second direction DR2 meet may berounded or right-angled. The planar shape of the display panel 100 isnot limited to a rectangular shape, and may be provided in otherpolygonal shapes, a circular shape or elliptical shape.

The display panel 100 may be flat, but is not limited thereto. In anembodiment, the display panel 100 may include a curved portion providedat left and right ends and having a predetermined curvature or a varyingcurvature, for example. In addition, the display panel 100 may beflexible, e.g., bendable, foldable, or rollable.

The display panel 100 may include a display area DPA and a non-displayarea NDA. The display area DPA is an area where a screen may bedisplayed, and the non-display area NDA is an area where a screen maynot be displayed. The display area DPA may also be referred to as anactive region, and the non-display area NDA may also be referred to as anon-active region. The display area DPA may substantially occupy thecenter of the display panel 100.

The display area DPA may include a plurality of pixels PX. The pluralityof pixels PX may be arranged in a matrix. However, the invention is notlimited thereto, and the plurality of pixels PX may be arranged invarious other forms. The shape of each pixel PX may be a rectangular orsquare shape in a plan view. However, the invention is not limitedthereto, and it may be a rhombic shape in which each side is inclinedwith respect to one direction. The pixels PX may be alternately arrangedin a stripe type or a pentile type. In addition, each of the pixels PXmay include one or more light emitting elements (EL in FIG. 5) that emitlight of a specific wavelength band to display a specific color.

The non-display areas NDA may be disposed around the display area DPA.The non-display areas NDA may completely or partially surround thedisplay area DPA. The display area DPA may have a rectangular shape, andthe non-display areas NDA may be disposed adjacent to four sides of thedisplay area DPA. The non-display areas NDA may form a bezel of thedisplay panel 100. Wirings or circuit drivers included in the displaypanel 100 may be disposed in each of the non-display areas NDA, orexternal devices may be disposed (e.g., mounted) thereon.

The display driver 200 outputs signals and voltages for driving thedisplay panel 100. In an embodiment, the display driver 200 may supplydata voltages to data lines. Further, the display driver 200 may supplydriving voltages to driving voltage lines and may supply scan controlsignals to a scan driver, for example. The display driver 200 may beprovided as an integrated circuit (“IC”) and attached onto the displaycircuit board 300. In an alternative embodiment, the display driver 200may be attached to the display panel 100 by a chip on glass (“COG”)method, a chip on plastic (“COP”) method, or an ultrasonic bondingmethod.

The display circuit board 300 may be disposed in the non-display areaNDA at one edge of the display panel 100. In an embodiment, the displaycircuit board 300 may be disposed in the non-display area NDA of thelower edge of the display panel 100, for example. The display circuitboard 300 may be bent to the bottom of the display panel 100, and oneedge of the display circuit board 300 disposed on the bottom surface ofthe display panel 100 may be attached to the bottom surface of thedisplay panel 100. Although not illustrated, the display circuit board300 may be attached to and fixed to the bottom surface of the displaypanel 100 through an adhesive member. The adhesive member may be apressure-sensitive adhesive. In an alternative embodiment, the displaycircuit board 300 may be omitted, and one edge of the display panel 100may be bent downward.

The display circuit board 300 may be attached onto display pads of thedisplay panel 100 using an anisotropic conductive film. Thus, thedisplay circuit board 300 may be electrically connected to the displaypads of the display panel 100. In an embodiment, the display circuitboard 300 may be a flexible film, such as a flexible printed circuitboard, a printed circuit board, or a chip on film.

The encapsulation substrate (second substrate) 500 is disposed on thedisplay panel 100. In an embodiment, the encapsulation substrate 500 maybe disposed to face and be spaced apart from the display panel 100 inthe third direction DR3, for example. The encapsulation substrate 500may have a planar area smaller than that of the display panel 100 andmay be disposed to cover at least the display area DPA of the displaypanel 100. The encapsulation substrate 500 may encapsulate the lightemitting elements EL (refer to FIG. 5) and the circuit elements disposedon the display panel 100 in cooperation with the sealing member 700 tobe described later. In addition, in some embodiments, a touch member, apolarizing member, or the like may be further disposed on theencapsulation substrate 500.

In an embodiment, the encapsulation substrate 500 may be a transparentplate or a transparent film. In an embodiment, the encapsulationsubstrate 500 may include a glass material, a quartz material, or thelike, for example. In some embodiments, the encapsulation substrate 500and the light emitting element EL may be spaced apart from each otherand an inert gas such as nitrogen gas may be filled therebetween.However, the invention is not limited thereto, and a filler or the likemay be filled in a separation space between the encapsulation substrate500 and the light emitting element EL.

The sealing member 700 may be disposed between the display panel 100 andthe encapsulation substrate 500. In an embodiment, the sealing member700 may be disposed in the non-display area NDA of the display panel 100to surround the display area DPA, for example. The sealing member 700may encapsulate the light emitting elements EL and the circuit elementsof the display panel 100 together with the encapsulation substrate 500.The sealing member 700 may couple the display panel 100 and theencapsulation substrate 500 to each other. The sealing member 700 may bedisposed on a metal wiring layer MTL disposed in the non-display areaNDA of the display panel 100. The sealing member 700 may be in contactwith the metal wiring layer MTL and the lower surface of theencapsulation substrate 500 to be combined therewith. However, theinvention is not limited thereto, and the sealing member 700 may not bein contact with the metal wiring layer MTL of the display panel 100 andmay couple the display panel 100 and the encapsulation substrate 500 toeach other in a region where the metal wiring layer MTL is not disposed.

In some embodiments, the sealing member 700 may be a hardened frit. Asused herein, the term “frit” may refer to a structure having glassproperties provided by melting and hardening glass powder to which anadditive is selectively added. A frit for bonding the display panel 100and the encapsulation substrate 500 to each other may be provided byplacing the glass powder between the display panel 100 and theencapsulation substrate 500 and performing a sintering and meltingprocess. Hereinafter, a case where the sealing member 700 is a hardenedfrit will be described by way of example.

Since the sealing member 700 is provided through a sintering and meltingprocess during a process of fabricating the display device 10, thedisplay panel 100 and the encapsulation substrate 500 may be coupled toeach other through physical bonding with the sealing member 700. In anembodiment, the display device 10 may include a fusion region in which aphysical boundary does not exist at a boundary between the sealingmember 700 and the encapsulation substrate 500 or the display panel 100.The sealing member 700 may be fused and bonded to at least theencapsulation substrate 500, and may include a fused portion having nophysical boundary in addition to a portion where a physical boundaryexists at a boundary with the display panel 100 and encapsulationsubstrate 500. The sealing member 700 may be coupled to the displaypanel 100 and the encapsulation substrate 500 with a stronger bondingforce by including the fused portion. In particular, the sealing member700 may have a stronger bonding force at the boundary with theencapsulation substrate 500, thereby improving durability of the displaydevice 10 against external impact. A more detailed description thereofwill be given later.

FIG. 4 is a schematic plan view of an embodiment of a display panel.

In FIG. 4, for simplicity of description, only pixels PX, scan lines SL,data lines DL, first scan control lines SCL1, second scan control linesSCL2, and a first scan driver 110, a second scan driver 120, the displaydriver 200, display pads DP, and fan-out lines FL of the display panel100 are illustrated.

Referring to FIG. 4, the display panel 100 may include a display areaDPA where pixels PX display an image, and a non-display area NDA that isa peripheral area of the display area DPA. The non-display area NDA maybe an area from the outside of the display area DPA to the edge of thedisplay panel 100.

The scan lines SL, the data lines DL and the pixels PX may be disposedin the display area DPA. The scan lines SL may extend in the firstdirection (X axis direction) and may be arranged side by side in thesecond direction (Y-axis direction) intersecting the first direction(X-axis direction), and the data lines DL may extend in the seconddirection (Y-axis direction) and may be arranged side by side in thefirst direction (X-axis direction).

Each of the pixels PX may be connected to at least one of the scan linesSL and one of the data lines DL. Each of the pixels PX may include thinfilm transistors including a driving transistor and at least oneswitching transistor, an OLED, and a capacitor. Each of the pixels PXmay receive a data voltage of the data line DL when a scan signal isapplied from the scan line SL, and supply a driving current to the OLEDaccording to the data voltage applied to the gate electrode of thedriving transistor, thereby emitting light. A detailed description ofthe pixels PX will be given later with reference to FIG. 5.

The first scan driver 110, the second scan driver 120, the displaydriver 200, the first scan control lines SCL1, the second scan controllines SCL2, and the fan-out lines FL may be disposed in the non-displayarea NDA.

The first scan driver 110 is connected to the display driver 200 throughthe first scan control lines SCL1. Thus, the first scan driver 110 mayreceive a first scan control signal of the display driver 200. The firstscan driver 110 generates scan signals according to the first scancontrol signal and supplies the scan signals to the scan lines SL.

The second scan driver 120 is connected to the display driver 200through the second scan control lines SCL2. Thus, the second scan driver120 may receive a second scan control signal of the display driver 200.The second scan driver 120 generates scan signals according to thesecond scan control signal and supplies the scan signals to the scanlines SL.

The first scan driver 110 may be connected to the scan lines SLconnected to the pixels PX of the display area DPA. The second scandriver 120 may be connected to the scan lines SL connected to the pixelsPX.

The fan-out lines FL connect the display pads DP to the data lines DL,the first scan driver 110, and the second scan driver 120. That is, thefan-out lines FL may be disposed between the display pads DP and thedata lines DL, between the display pads DP and the first scan driver110, and between the display pads DP and the second scan driver 120.

A pad area PDA may include the display pads DP. The pad area PDA may bedisposed at one edge of the substrate. In an embodiment, the pad areaPDA may be disposed at the lower edge of the substrate, for example.

FIG. 5 is a cross-sectional view illustrating one pixel of FIG. 4.

Referring to FIG. 5, the display panel 100 may include a base substrate101, and a thin film transistor T1 and a light emitting element ELdisposed on the base substrate 101. Each pixel PX of the display panel100 may include at least one thin film transistor T1 and the lightemitting element EL, and may be connected to the scan line SL and thedata line DL. Although it is illustrated in the drawing that one thinfilm transistor T1 is disposed in one pixel PX, the invention is notlimited thereto.

The base substrate 101 may be a rigid substrate. In an embodiment, thebase substrate 101 may include an insulating material such as glass,quartz, or a polymer resin. Examples of a polymeric material may includepolyethersulphone (“PES”), polyacrylate (“PA”), polyarylate (“PAR”),polyetherimide (“PEI”), polyethylene naphthalate (“PEN”), polyethyleneterephthalate (PET”), polyphenylene sulfide (“PPS”), polyallylate,polyimide (“PI”), polycarbonate (“PC”), cellulose triacetate (“CAT”),cellulose acetate propionate (“CAP”), or any combinations thereof. Thebase substrate 101 may include a metal material.

A buffer layer 102 may be disposed on the base substrate 101. The bufferlayer 102 may be disposed on the base substrate 101 to protect the thinfilm transistors T1 and the light emitting elements from moisturepenetrating through the base substrate 101 susceptible to moisturepermeation. The buffer layer 102 may include a plurality of inorganiclayers that are alternately stacked. In an embodiment, the buffer layer102 may include a multilayer in which one or more inorganic layers of asilicon oxide (SiOx) layer, a silicon nitride (SiNx) layer and a siliconoxynitride (SiON) layer are alternately stacked, for example. In anotherembodiment, the buffer layer 102 may be omitted.

The thin film transistor T1 is disposed on the buffer layer 102. Eachthin film transistor T1 may include an active layer ACT1, a gateelectrode GI, a source electrode Si, and a drain electrode D1. AlthoughFIG. 5 illustrates that the thin film transistor T1 is provided by a topgate method in which the gate electrode G1 is disposed above the activelayer ACT1, the invention is not limited thereto. That is, the thin filmtransistor T1 may be provided by a bottom gate method in which the gateelectrode G1 is disposed below the active layer ACT1, or a double gatemethod in which the gate electrode G1 is disposed both above and belowthe active layer ACT1.

The active layer ACT1 is disposed on the buffer layer 102. The activelayer ACT1 may include a silicon-based semiconductor material or anoxide-based semiconductor material. Although not shown, a light blockinglayer may be provided between the buffer layer 102 and the active layerACT1 to block external light incident on the active layer ACT1.

A gate insulating layer 103 may be disposed on the active layer ACT1. Inan embodiment, the gate insulating layer 103 may include an inorganiclayer such as a silicon oxide (SiOx) layer, a silicon nitride (SiNx)layer, or a multilayer thereof.

The gate electrode G1 and a gate line may be disposed on the gateinsulating layer 103. In an embodiment, the gate electrode G1 and thegate line may be provided as a single layer or multiple layers includingany one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au),titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) or an alloythereof.

An inter-insulating layer 105 may be disposed on the gate electrode G1and the gate line. In an embodiment, the inter-insulating layer 105 mayinclude an inorganic layer such as a silicon oxide (SiOx) layer and asilicon nitride (SiNx) layer, or a multilayer thereof.

The source electrode Si, the drain electrode D1, and the data line maybe disposed on the inter-insulating layer 105. Each of the sourceelectrode Si and the drain electrode D1 may be connected to the activelayer ACT1 through a contact hole penetrating through the gateinsulating layer 103 and the inter-insulating layer 105. In anembodiment, the source electrode S, the drain electrode D1, and the dataline may be provided as a single layer or multiple layers including anyone of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au),titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) or an alloythereof, for example.

A passivation layer 107 may be disposed on the source electrode Si, thedrain electrode D1, and the data line to insulate the thin filmtransistor T1. In an embodiment, the passivation layer 107 may includean inorganic layer such as a silicon oxide (SiOx) layer and a siliconnitride (SiNx) layer, or a multilayer thereof.

A planarization layer 108 is disposed on the passivation layer 107. Theplanarization layer 108 may planarize a step due to the thin filmtransistor T1. In an embodiment, the planarization layer 108 may includean organic layer such as acryl resin, epoxy resin, phenolic resin,polyamide resin, polyimide resin and the like.

A pixel defining layer 109 and the light emitting element EL aredisposed on the planarization layer 108.

The light emitting element EL may be an organic light emitting element.In this case, the light emitting element EL may include an anodeelectrode AND, light emitting layers OL, and a cathode electrode CTD.

The anode electrode AND may be disposed on the planarization layer 108.The anode electrode AND may be connected to the source electrode Si ofthe thin film transistor T1 through a contact hole penetrating thepassivation layer 107 and the planarization layer 108.

The pixel defining layer 109 may cover the edge of the anode electrodeAND on the planarization layer 108 to partition the pixels. That is, thepixel defining layer 109 serves as a pixel defining layer for definingpixels. Each of the pixels represents a region where the anode electrodeAND, the light emitting layer OL and the cathode electrode CTD arestacked sequentially and holes from the anode electrode AND andelectrons from the cathode electrode CTD are coupled to each other inthe light emitting layer OL to emit light.

The light emitting layers OL are disposed on the anode electrode AND andthe pixel defining layer 109. The light emitting layer OL may be anorganic light emitting layer. In an embodiment, the light emitting layerOL may emit one of red light, green light and blue light, for example.In an alternative embodiment, the light emitting layer OL may be a whitelight emitting layer that emits white light. In this case, the lightemitting layer OL may have a structure in which a red light emittinglayer, a green light emitting layer, and a blue light emitting layer arestacked, and may be a common layer provided commonly to the pixels. Inthis case, the display panel 100 may further include a separate colorfilter for displaying a red, green or blue color.

The light emitting layer OL may include a hole transporting layer, alight emitting layer, and an electron transporting layer. In addition,the light emitting layer OL may be provided in a tandem structure of twoor more stacks, in which case a charge generating layer may be providedbetween the stacks.

The cathode electrode CTD is disposed on the light emitting layer OL.The cathode electrode CTD may cover the light emitting layer OL. Thecathode electrode CTD may be a common layer provided commonly to thepixels.

In a case where the light emitting element EL of the display panel 100is provided by a top emission method in which light is emitted upward,the anode electrode AND may include a metal material having highreflectivity to have a stacked structure (Ti/Al/Ti) of aluminum andtitanium, a stacked structure (“ITO/Al/ITO”) of aluminum and indium tinoxide (“ITO”), an silver-palladium-copper (“APC”) alloy, and a stackedstructure (“ITO/APC/ITO”) of an APC alloy and ITO. The APC alloy is analloy of silver (Ag), palladium (Pd) and copper (Cu). Further, thecathode electrode CTD may include a transparent conductive oxide (“TCO”)material such as ITO or indium zinc oxide (“IZO”) that may transmitlight or a semi-transmissive conductive material such as magnesium (Mg),silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). In a casewhere the cathode electrode CTD includes a semi-transmissive conductivematerial, the light emission efficiency may be increased due to amicro-cavity effect.

In a case where the light emitting element EL is provided by a bottomemission method in which light is emitted downward, the anode electrodeAND may include a TCO material such as ITO or IZO or a semi-transmissiveconductive material such as magnesium (Mg), silver (Ag), or an alloy ofmagnesium (Mg) and silver (Ag). The cathode electrode CTD may include ametal material, having high reflectivity, such as a stacked structure(Ti/Al/Ti) of aluminum (Al) and titanium (Ti), a stacked structure(“ITO/Al/ITO”) of Al and ITO, an APC alloy, a stacked structure(“ITO/APC/ITO”) of an APC alloy and ITO, or the like. In a case wherethe anode electrode AND includes a semi-transmissive conductivematerial, the light emission efficiency may be increased due to amicro-cavity effect.

FIG. 6 is a schematic plan view illustrating an embodiment of a displaydevice having a sealing member disposed therein. FIG. 7 is across-sectional view taken along line I-I′ of FIG. 6. FIG. 8 is across-sectional view taken along line II-II′ of FIG. 6. FIGS. 7 and 8illustrate cross sections of a portion of the non-display area NDA ofthe display panel 100 disposed in the first direction DR1 of the displayarea DPA and a portion of the non-display area NDA of the display panel100 adjacent to the pad area PDA in the other side of the seconddirection DR2.

Referring to FIGS. 6 to 8, the sealing member 700 of the display device10 may be disposed in the non-display area NDA to form a closed curve ina plan view and surround the display area DPA of the display panel 100.That is, the sealing member 700 may surround the light emitting elementsEL (refer to FIG. 5) disposed in the display area DPA, and may seal aspace between the encapsulation substrate 500 and the display panel 100.The sealing member 700 may prevent damage to the light emitting elementEL due to air, moisture or the like in cooperation with theencapsulation substrate 500.

In an embodiment, the sealing member 700 may be disposed on the metalwiring layer MTL disposed in the non-display area NDA of the displaypanel 100. The metal wiring layer MTL may be disposed on theinter-insulating layer 105 of the display panel 100 in the non-displayarea NDA. As described above, the first scan driver 110, the second scandriver 120, the fan-out lines FL and the like may be disposed in thenon-display area NDA of the display panel 100. The metal wiring layerMTL disposed in the non-display area NDA may be any one of the firstscan driver 110, the second scan driver 120 and the fan-out lines FL,and the sealing member 700 may be disposed to overlap the metal wiringlayer MTL. In an embodiment, the metal wiring layer MTL illustrated inFIG. 7 may be any one of circuit elements or wirings disposed in thefirst scan driver 110 or the second scan driver 120, and the metalwiring layer MTL illustrated in FIG. 8 may be any one of the fan-outlines FL and the display pads DP connected thereto, for example.However, the invention is not limited thereto.

FIGS. 7 and 8 illustrate that the metal wiring layer MTL is disposedalong the non-display area NDA, and the width of the sealing member 700(taken along the first direction DR1 in FIG. 7) is the same as the widthof the metal wiring layer MTL (taken along the first direction DR1 inFIG. 7) such that the lower surface of the sealing member 700 isentirely in contact with the metal wiring layer MTL, but the inventionis not limited thereto. The metal wiring layer MTL may have a widthsmaller than that of the sealing member 700, and the sealing member 700may be in direct contact with the inter-insulating layer 105 of thedisplay panel 100. A description thereof may refer to other embodiments.

The display panel 100 and the encapsulation substrate 500 of the displaydevice 10 may be coupled to each other through the sealing member 700.The sealing member 700 may include a frit to couple the display panel100 and the encapsulation substrate 500 to each other through physicalbonding, and may include a physical boundary between the sealing member700 and the display panel 100 or the encapsulation substrate 500.However, the display device 10 in an embodiment may include a fusionregion MA in which the sealing member 700 is fused with theencapsulation substrate 500 or the display panel 100 such that aphysical boundary does not exist therebetween.

FIG. 9 is an enlarged view of portion A of FIG. 7.

Referring to FIG. 9 in conjunction with FIGS. 7 and 8, the sealingmember 700 may include a portion that is physically bonded at theboundary between the encapsulation substrate 500 and the display panel100 or the metal wiring layer MTL of the display panel 100. That is, thesealing member 700 may be in direct contact with the display panel 100and the encapsulation substrate 500, and a physical boundary may existin a region where they are in contact with each other. In an embodiment,a physical boundary exists between the lower surface of theencapsulation substrate 500 and the upper surface of the sealing member700, and between the upper surface of the display panel 100, and thelower surface of the sealing member 700, for example. The sealing member700 may be in direct contact with the display panel 100 and theencapsulation substrate 500 to be bonded thereto.

In an embodiment, the sealing member 700 may include the fusion regionMA provided at least at the boundary with the encapsulation substrate500. The fusion region MA may be provided in at least a portion of theboundary provided by the sealing member 700 and the encapsulationsubstrate 500. The fusion region MA may be a region where no physicalboundary exists between the sealing member 700 and the encapsulationsubstrate 500, and may be a region provided by mixing a material of thesealing member 700 with a material of the encapsulation substrate 500.As described above, the encapsulation substrate 500 may include amaterial such as glass, and the sealing member 700 including a frit mayinclude a material similar to the encapsulation substrate 500. In thefusion region MA, a portion of the material of the sealing member 700may be introduced into the encapsulation substrate 500, a portion of thematerial of the encapsulation substrate 500 may be introduced into thesealing member 700, and they may be mixed with each other. Accordingly,in a portion where the fusion region MA is provided, a physical boundarybetween the upper surface of the sealing member 700 and the lowersurface of the encapsulation substrate 500 may not exist, and thematerials of the sealing member 700 and the encapsulation substrate 500may be mixed to form the fusion region MA. As a result, a bonding forcebetween the sealing member 700 and the encapsulation substrate 500 maybe improved.

The sealing member 700 may include a first boundary surface CS1 thatforms a physical boundary with the upper surface of the display panel100 or the upper surface of the metal wiring layer MTL, and a secondboundary surface CS2 that forms a physical boundary with the lowersurface of the encapsulation substrate 500. The fusion region MA isprovided between the sealing member 700 and the encapsulation substrate500. A third boundary surface CS3 may be between the sealing member 700and the fusion region MA, and a fourth boundary surface CS4 may beprovided between the encapsulation substrate 500 and the fusion regionMA. The first boundary surface CS1 and the second boundary surface CS2are surfaces where the sealing member 700 is in contact with the displaypanel 100 and the encapsulation substrate 500, respectively, and may beboundaries where the sealing member 700, the display panel 100 and theencapsulation substrate 500 are physically divided. In the firstboundary surface CS1 and the second boundary surface CS2, the materialof the sealing member 700 does not move to the display panel 100 or theencapsulation substrate 500, or is not mixed with the material of thedisplay panel 100 or the encapsulation substrate 500. The sealing member700 may maintain a state where the sealing member 700 is bonded to thedisplay panel 100 and the encapsulation substrate 500 at the firstboundary surface CS1 and the second boundary surface CS2, respectively.

The fusion region MA is a region where the materials of the sealingmember 700 and the encapsulation substrate 500 are mixed. A portion (NPAin FIG. 9) where the physical boundary does not exist may be provided ina portion in which the fusion region MA is provided in the extendedportion of the second boundary surface CS2. That is, at least a portionof the boundary between the sealing member 700 and the encapsulationsubstrate 500 may have no physical boundary, and the fused region MA maybe provided therein. The third boundary surface CS3 and the fourthboundary surface CS4 may be boundary surfaces provided with the fusionregion MA in the sealing member 700 and the encapsulation substrate 500,respectively.

In an embodiment, the fusion region MA may be provided by mixing thematerials of the sealing member 700 and the encapsulation substrate 500.Unlike the first boundary surface CS1 and the second boundary surfaceCS2, the third boundary surface CS3 and the fourth boundary surface CS4may be boundaries where there are component differences according topositions, rather than physical boundaries. The fusion region MA is aregion where the materials of the encapsulation substrate 500 and thesealing member 700 are mixed with each other. The fusion region MA maybe a region provided as the material of the sealing member 700 moves tothe encapsulation substrate 500, and the material of the encapsulationsubstrate 500 moves toward the sealing member 700. Since all thematerials of the sealing member 700 and the encapsulation substrate 500are included and mixed in the fusion region MA, all of the materials maybe detected in the fusion region MA. In an embodiment, a frit componentwhich is a first component of the sealing member 700 and a glasscomponent which is a second component of the encapsulation substrate 500may be detected in a mixed state in the fusion region MA, respectively,for example. Since only the frit component is detected in the sealingmember 700 and only the glass component is detected in the encapsulationsubstrate 500, the third boundary surface CS3 and the fourth boundarysurface CS4 of the fusion region MA may have a boundary due to acomponent difference, rather than a physical boundary.

In an embodiment, the fusion region MA may include the second componentof the encapsulation substrate 500 in an amount greater than that of thesealing member 700 on the basis of the third boundary surface CS3, andthe fusion region MA may include the first component of the sealingmember 700 in an amount greater than that of the encapsulation substrate500 on the basis of the fourth boundary surface CS4. However, on thebasis of the third boundary surface CS3 and the fourth boundary surfaceCS4, since the sealing member 700 and the fusion region MA include acommon component and the fusion region MA and the encapsulationsubstrate 500 include a common component, a physical boundary may notexist.

The fusion region MA may be provided by partially fusing the sealingmember 700 and the encapsulation substrate 500 by an intense light(e.g., laser) irradiated from the upper surface of the encapsulationsubstrate 500 during a process of fabricating the display device 10. Thelaser may be set such that its focal point is separated from the uppersurface of the encapsulation substrate 500, and mixing of the materialsmay occur at the boundary between the encapsulation substrate 500 andthe sealing member 700. A description thereof will be given later.

As the fusion region MA is provided by the laser irradiated from theupper surface of the encapsulation substrate 500, the laser may notreach the metal wiring layer MTL disposed on the display panel 100. Inan embodiment, the fusion region MA may overlap the metal wiring layerMTL in the thickness direction, but may be spaced apart from the metalwiring layer MTL. At least a portion of the sealing member 700 may bedisposed on the metal wiring layer MTL, and the fusion region MA mayoverlap the metal wiring layer MTL in the thickness direction. However,the fusion region MA may be separated from the metal wiring layer MTL soas not to be in direct contact with the metal wiring layer MTL. Thedisplay device 10 includes the fusion region MA in which a physicalboundary does not exist at the boundary between the sealing member 700and the encapsulation substrate 500, and the bonding force between thedisplay panel 100 and the encapsulation substrate 500 may be improvedwithout damaging the metal wiring layer MTL disposed on the displaypanel 100.

Further, the width WM of the fusion region MA may vary from theencapsulation substrate 500 to the sealing member 700. In an embodiment,the fusion region MA may include a first portion (e.g., a lower portionof the fusion region MA in FIGS. 7 to 9) overlapping the sealing member700 and a second portion (e.g., a upper portion of the fusion region MAin FIGS. 7 to 9) overlapping the encapsulation substrate 500, and themaximum value of a width W1 of the first portion may be greater than themaximum value of a width W2 of the second portion. As described above,the fusion region MA may be provided by a laser irradiated from theupper surface of the encapsulation substrate 500, and the focal point ofthe laser may be set to be separated from the upper surface of theencapsulation substrate 500. From the upper surface of the encapsulationsubstrate 500 to the sealing member 700, the range in which the laser isirradiated may be widened, and thus, mixing between materials of theencapsulation substrate 500 and the sealing member 700 may occur in awider region. The fusion region MA may be disposed over theencapsulation substrate 500 and the sealing member 700, and may have awidth increasing from the second portion overlapping the encapsulationsubstrate 500 to the first portion overlapping the sealing member 700.As shown in FIG. 9, the fusion region MA may have a shape in which thewidth of the first portion is larger than that of the second portion incross-sectional view. However, the invention is not limited thereto.

The fusion region MA may have a width WM and a height HM varyingdepending on a thickness HA of the sealing member 700. In an embodiment,the height of the fusion region MA may be greater than the thickness ofthe sealing member 700. However, the fusion region MA may be separatedfrom the metal wiring layer MTL while overlapping the metal wiring layerMTL in the thickness direction, and the height H1 of the first portion(e.g., a lower portion of the fusion region MA in FIG. 9) overlappingthe sealing member 700 may be smaller than the thickness HA of thesealing member 700. As the height of the fusion region MA increases, thebonding force between the encapsulation substrate 500 and the sealingmember 700 may be further improved.

In some embodiments, the thickness HA of the sealing member 700 mayrange from about 4.5 micrometers (μm) to about 6 μm, or about 5 μm, andthe width WM and the height HM of the fusion region MA may range fromabout 8 μm to about 12 μm, or about 10 μm, for example. Further, theheight H1 of the first portion of the fusion region MA may be smallerthan the thickness of the sealing member 700 and may range from about 2μm to about 4 μm such that the display panel 100 or the metal wiringlayer MTL may be separated from the fusion region MA, for example.However, the invention is not limited thereto, and the width WM and theheight HM of the fusion region MA may vary depending on the intensity ofthe laser irradiated during the process of fabricating the displaydevice 10.

The sealing member 700 may be disposed along the non-display area NDA ofthe display panel 100 to form a closed curve to surround the displayarea DPA, and the fusion regions MA may be disposed along the sealingmember 700 and spaced apart from each other to form a pattern on theentire surface of the sealing member 700.

FIG. 10 is a schematic plan view illustrating the arrangement of fusionregions provided in a sealing member of a display device. FIG. 11 is across-sectional view taken along line III-III′ of FIG. 10.

Referring to FIGS. 10 and 11, the display device 10 in an embodiment mayinclude a first extension portion in which the sealing member 700extends in the first direction DR1 along the non-display area NDA, asecond extension portion in which the sealing member 700 extends in thesecond direction DR2 along the non-display area NDA, and at least onecorner portion having a curvature connected to the first extensionportion and the second extension portion. The sealing member 700 mayform a closed curve to surround the display area DPA. The sealing member700 may include the first extension portion and the second extensionportion corresponding to the short side of the display panel 100extending in the first direction DR1 and the long side of the displaypanel 100 extending in the second direction DR2. Further, the sealingmember 700 may include a first corner portion in which a corner portionwhere the first extension portion and the second extension portion meetis curved.

The fusion regions MA may be provided between the sealing member 700 andthe encapsulation substrate 500 to be spaced apart from each other alongthe sealing member 700. In an embodiment, the plurality of fusionregions MA may be spaced apart from each other to form a pattern, andthe fusion regions MA may be provided along at least the first cornerportion of the sealing member 700. In the sealing member 700, whichcouples the display panel 100 and the encapsulation substrate 500 toeach other, the fusion regions MA are provided at the first cornerportion where the first extension portion and the second extensionportion meet, thereby further improving the durability at the firstcorner portion having a relatively weak bonding force. Although FIG. 10illustrates that the fusion regions MA having the shape of FIG. 9 arespaced apart from each other to form a pattern, the invention is notlimited thereto. The fusion regions MA may have different shapes in aplan view, and the plurality of fusion regions MA may be connected toeach other without being spaced apart from each other to have apredetermined length, or may form a closed curve along the sealingmember 700. In addition, although it is illustrated in FIG. 10 that onlyone fusion region MA is provided along the first direction DR1, which isthe width direction of the sealing member 700, in a left side or a rightside of the sealing member 700 and only one fusion region MA is providedalong the second direction DR2, which is the width direction of thesealing member 700, in an upper side or a lower side of the sealingmember 700, the invention is not limited thereto. The plurality offusion regions MA may be provided along the width direction of thesealing member 700, and may be spaced apart from each other.

When the plurality of fusion regions MA is spaced apart from each other,an interval (DM of FIG. 11), at which the fusion regions MA are spacedapart from each other, may be larger than the maximum value of the widthWM (refer to FIG. 9) of the fusion region MA. In an embodiment, theinterval DM at which the plurality of fusion regions MA are spaced apartfrom each other may be greater than the maximum value of the width WM ofthe fusion region MA, and in some embodiments, the interval DM at whichthe plurality of fusion regions MA are spaced apart from each other mayrange from about 50 μm to about 100 μm, for example. However, theinvention is not limited thereto.

Hereinafter, a method of fabricating the display device 10 in anembodiment will be described.

FIG. 12 is a flowchart showing an embodiment of a method for fabricatinga display device.

Referring to FIG. 12, in an embodiment, the method of fabricating thedisplay device 10 includes preparing the display panel 100 and theencapsulation substrate 500 (operation S100), bonding the display panel100 and the encapsulation substrate 500 via the sealing member 700,irradiating a laser to the sealing member 700 to form the fusion regionMA having no physical boundary between the encapsulation substrate 500and the sealing member 700. The operation of bonding the display panel100 and the encapsulation substrate 500 to each other may includepreparing frit crystals (operation S200) therebetween and melting thefrit crystals by irradiating a laser to the frit crystals aftersintering. Here, the laser irradiated to melt the frit crystals may havean intensity different from the laser irradiated to form the fusionregion MA. Amore detailed description thereof will be made withreference to other drawings.

FIGS. 13 to 16 are cross-sectional views illustrating an embodiment of aprocess of fabricating a display device.

First, referring to FIG. 13 in conjunction with FIG. 12, the displaypanel 100 and the encapsulation substrate 500 are prepared (operationS100), and frit crystals 710 are prepared between the display panel 100and the encapsulation substrate 500 (operation S200). The frit crystals710 may be prepared by performing printing, drying and sinteringprocesses on the non-display area NDA of the display panel 100, i.e.,the outside of the display area DPA. In some embodiments, the fritcrystals 710 may be glass powder to which an additive is selectivelyadded. As described above, the sealing member 700 may include a frit,and the frit crystals 710 may be melted and hardened to form a structurehaving glass properties, thereby forming the sealing member 700.

Subsequently, referring to FIG. 14, the frit crystals 710 are irradiatedwith a first laser to form the sealing member 700, thereby bonding theencapsulation substrate 500 to the display panel 100 (operation S300).The first laser may be irradiated from the upper surface of theencapsulation substrate 500 or the lower surface of the display panel100. The encapsulation substrate 500 may include a transparent material,and the first laser may be irradiated to the frit crystals 710 afterpassing through the encapsulation substrate 500. Also in the case of thedisplay panel 100, the base substrate 101 may include a transparentmaterial, and the first laser may be irradiated to at least the metalwiring layer MTL. The metal wiring layer MTL includes a metal material,and when the first laser is irradiated thereto, heat may be generatedand transferred to the frit crystals 710. That is, the first laserirradiated from the upper surface of the encapsulation substrate 500 orthe lower surface of the display panel 100 may transfer energy to thefrit crystals 710 directly or indirectly, and the frit crystals 710 mayform the sealing member 700 through a melting and hardening process.Although it is illustrated in the drawing that the first laser isirradiated from the upper surface of the encapsulation substrate 500 andthe lower surface of the display panel 100, the invention is not limitedthereto. In some embodiments, the first laser may be irradiated fromonly one of the upper surface of the encapsulation substrate 500 and thelower surface of the display panel 100, or may be irradiated fromanother direction, e.g., from the side of the frit crystals 710.

When the first laser is irradiated, only the frit crystals 710 aremelted and the display panel 100 or the metal wiring layer MTL and theencapsulation substrate 500 are not melted. The sealing member 700provided from the frit crystals 710 through the melting and curingprocess may be physically bonded to the display panel 100 or the metalwiring layer MTL and the encapsulation substrate 500. When the fritcrystals 710 are melted, the frit crystals 710 are transformed into astate having a viscosity. When the frit crystals 710 are hardened againto form the sealing member 700, while the frit crystals 710 lose theviscosity, the metal wiring layer MTL and the encapsulation substrate500 may be bonded to the sealing member 700. The sealing member 700 maybe in direct contact with the metal wiring layer MTL and theencapsulation substrate 500 to bond the metal wiring layer MTL and theencapsulation substrate 500 to each other and a physical boundary mayexist at the boundary between the sealing member 700 and the metalwiring layer MTL and at the boundary between the sealing member 700 andthe encapsulation substrate 500.

Subsequently, referring to FIGS. 14 and 15, the sealing member 700 isirradiated with a second laser to form the fusion region MA, and thesealing member 700 and the encapsulation substrate 500 are partiallyfused (operation S400). The second laser may be selectively irradiatedat the boundary between the encapsulation substrate 500 and the sealingmember 700 to form the fusion region MA having no physical boundary. Inan embodiment, the second laser may be a pulsed laser having a strongerintensity than that of the first laser. In some embodiments, the secondlaser may be irradiated at a frequency of about 1 kilohertz (kHz) toabout 10 MHz for about 10 femtoseconds (fs) to about 50 picoseconds(ps), and may have an energy of about 0.1 microjoule (μJ) or more, forexample. The second laser may partially fuse the materials of theencapsulation substrate 500 and the sealing member 700 at the boundarybetween the encapsulation substrate 500 and the sealing member 700. Thefusion region MA may be a region where the material of the sealingmember 700 and the material of the encapsulation substrate 500 are mixedwith each other, and may be a region having no physical boundary betweenthe sealing member 700 and the encapsulation substrate 500.

The second laser may be irradiated from the upper surface of theencapsulation substrate 500 without damaging the metal wiring layer MTLof the display panel 100. In an embodiment, a focal point AFP of thesecond laser may be set to be separated from the upper surface of theencapsulation substrate 500, and a distance FLD between the uppersurface of the encapsulation substrate 500 and the focal point AFP ofthe second laser may range from about 0.1 μm to about 200 μm, forexample. Since the second laser has a stronger intensity than that ofthe first laser, when the focal point AFP of the second laser is setinside the encapsulation substrate 500 or between the sealing member 700and the encapsulation substrate 500, the metal wiring layer MTL of thedisplay panel 100 MTL may be damaged. In an embodiment, the second laseris set such that the focal point AFP is separated from the upper surfaceof the encapsulation substrate 500, i.e., outside the display device 10.Thus, even though the second laser is irradiated to the boundary betweenthe sealing member 700 and the encapsulation substrate 500, the fusionregion MA may be separated from the metal wiring layer MTL, it ispossible to prevent damage to the metal wiring layer MTL.

Further, when the second laser reaches the boundary between the sealingmember 700 and the encapsulation substrate 500 through the focal pointAFP, energy may be transferred to spread to a wider area than that ofthe focal point AFP. The fusion region MA provided at the boundarybetween the sealing member 700 and the encapsulation substrate 500 mayhave a shape in which the width increases from the focal point AFP ofthe second laser to the sealing member 700, or from the encapsulationsubstrate 500 to the sealing member 700.

The method of fabricating the display device 10 in an embodiment mayinclude forming the fusion region MA by irradiating the second laserafter the display panel 100 and the encapsulation substrate 500 arebonded to each other via the sealing member 700. The display device 10includes the fusion region MA having no physical boundary at leastbetween the encapsulation substrate 500 and the sealing member 700, andthe bonding force between the sealing member 700 and the encapsulationsubstrate 500 may be improved, thereby improving durability of thedisplay device 10 against external impact.

Hereinafter, various embodiments of the display device 10 will bedescribed with reference to other drawings.

FIG. 17 is a cross-sectional view illustrating another embodiment of aportion of a display device. FIG. 18 is a cross-sectional view partiallyillustrating a process of fabricating the display device of FIG. 17.

Referring to FIGS. 17 and 18, a display device 10_1 in an embodiment mayinclude a greater number of fusion regions MA_1 provided in the widthdirection of a sealing member 700_1. The embodiment of FIGS. 17 and 18differs from the embodiment of FIG. 7 in that a larger number of fusionregions MA_1 is provided in the width direction of the sealing member700_1. In the following description, a redundant description will beomitted and differences will be mainly described.

The sealing member 700_1 of the display device 10_1 may have a widthmeasured in the first direction DR1. In the embodiment of FIG. 7, onefusion region MA is provided in the width direction of the sealingmember 700_1. However, the invention is not limited thereto, and aplurality of second lasers (2nd Lasers in FIG. 18) may be irradiated inthe width direction of the sealing member 700_1, and the display device101 may include a plurality of fusion regions MA_1 spaced apart fromeach other in the width direction of the sealing member 700_1. Thefusion regions MA_1 may include a first fusion region MA1_1 adjacent tothe display area DPA, a third fusion region MA3_1 provided at theoutermost side of the non-display area NDA, and a second fusion regionMA2_1 provided therebetween. The first to third fusion regions MA1_1,MA2_1 and MA3_1 may be spaced apart from each other in the firstdirection DR1. In addition, although not shown in the drawings, each ofthe first to third fusion regions MA_1, MA2_1 and MA3_1 may be providedplurally along the second extension portion of the sealing member 700_1,and these may form patterns spaced apart from each other in the seconddirection DR2, respectively. In an embodiment, the display device 10_1includes a greater number of fusion regions MA_1 arranged along thewidth direction of the sealing member 700_1, and thus the bonding forcebetween the sealing member 700_1 and the encapsulation substrate 500 maybe further improved.

FIGS. 19 to 21 are schematic plan views illustrating the arrangement offusion regions provided in a sealing member of a display deviceaccording to other embodiments.

Referring to FIGS. 19 to 21, the planar shape of the fusion region MAmay be variously modified. First, referring to FIG. 19, a display device10_2 in an embodiment may include a fusion region MA_2 having a shape inwhich portions extending in the first direction DR1 and the seconddirection DR2 intersect each other. The fusion region MA_2 having theabove-described shape may be provided by controlling the focal point AFPand the laser width of the second laser in the process of irradiatingthe second laser. In an embodiment, when irradiating the second laser,by irradiating a laser having a width in the first direction DR1 andthen irradiating a laser having a width in the second direction DR2intersecting the first direction DR1, the fusion region MA_2 having theshape shown in FIG. 19 may be provided, for example. However, theinvention is not limited thereto, and the shape of the fusion regionMA_2 may be variously modified.

Referring to FIG. 20, a display device 10_3 may include a fusion regionMA_3 which forms a closed curve to surround the display area DPA byextending the fusion region MA_3 along the sealing member 700. Thefusion region MA_3 may be provided entirely at the boundary between thesealing member 700 and the encapsulation substrate 500, and may besubstantially provided in the same shape as the sealing member 700. Thefusion region MA_3 may include extension portions extending in the firstdirection DR1 and the second direction DR2 and a corner portion having acurvature at a portion where the extension portions meet. However, thewidth WM of the fusion region MA_3 may be smaller than the width of thesealing member 700, and at least a portion of the sealing member 700 maybe in direct contact with the encapsulation substrate 500. In theembodiment of FIG. 20, since the fusion region MA_3 is provided over theentire area of the sealing member 700, the bonding force between theencapsulation substrate 500 and the sealing member 700 may be furtherimproved.

However, the invention is not limited thereto, and the fusion region MAmay be selectively provided only at a portion where the bonding force ofthe sealing member 700 and the encapsulation substrate 500 is weak.

A display device 10_4 of FIG. 21 may include a fusion region MA_4provided on each corner portion where the first and second extensionportions of the sealing member 700 meet. The fusion region MA_4 may havea curved shape according to the shape of the corner portion of thesealing member 700. The corner portion of the sealing member 700 may bea portion having a weak bonding force with the encapsulation substrate500 and having a high frequency of damage due to external impact. In aprocess of fabricating the display device 10_4, by selectivelyirradiating the second laser only to a region susceptible to externalimpact in the boundary between the sealing member 700 and theencapsulation substrate 500, the fusion region MA_4 may be provided onlyin the corresponding region.

FIG. 22 is a schematic plan view illustrating another embodiment of thearrangement of fusion regions provided in a sealing member of a displaydevice in another embodiment.

Referring to FIG. 22, a display device 10_5 may be configured such thata trench portion TP is defined in a display panel 100_5 and anencapsulation substrate 500_5. The trench portion TP may be defined inthe display panel 100_5 and the encapsulation substrate 500_5 such thatone short side of the short sides extending in the first direction DR1,which is disposed at an upper side from the center, is recessed inward.Accordingly, the non-display area NDA of the display panel 100_5 mayhave more corner portions, and the encapsulation substrate 500_5 mayhave more portions susceptible to external impact. In the display device10_5 in an embodiment, the trench portion TP may be defined in thedisplay panel 100_5 and the encapsulation substrate 500_5, and thefusion region MA_5 may be provided in the corner portion of the sealingmember 700 corresponding to the trench portion TP. The fusion regionMA_5 may correspond to each of the curved corner portions of the trenchportion TP, and even when the display panel 100_5 and the encapsulationsubstrate 500_5 are deformed, the bonding force between the sealingmember 700 and the encapsulation substrate 500_5 may be improved.

As described above, the metal wiring layer MTL disposed in thenon-display area NDA may be the first scan driver 110, the second scandriver 120, the fan-out lines FL, and the like. In the above-describeddrawings, only the embodiment in which the metal wiring layer MTL isdisposed on the entire surface of the non-display area NDA such that thelower surface of the sealing member 700 is entirely in contact with themetal wiring layer MTL is illustrated. However, the invention is notlimited thereto, and the metal wiring layer MTL may have a shape havingpatterns spaced apart from each other at a predetermined interval. Inthe non-display area NDA, a portion of the insulating layer on which themetal wiring layer MTL is disposed, e.g., the inter-insulating layer105, may be exposed. The exposed inter-insulating layer 105 may be indirect contact with the sealing member 700.

FIG. 23 is an enlarged schematic view of a portion SDA1 of FIG. 10. FIG.24 is an enlarged schematic view of a portion SDA2 of FIG. 10. FIG. 25is a cross-sectional view taken along line IV-IV′ of FIG. 23. In FIG.10, the portion SDA1 may be a portion in which the first scan driver 110or the second scan driver 120 is disposed in the non-display area NDA,and the portion SDA2 may be a portion in which the fan-out lines FL aredisposed in the non-display area NDA.

Referring to FIGS. 23 to 25, the metal wiring layer MTL disposed in thenon-display area NDA may form patterns partially spaced apart from eachother, and the sealing member 700 may be in direct contact with aportion of the display panel 100 where the metal wiring layer MTL is notdisposed. In an embodiment, the display panel 100 may include at leastone insulating layer 102, 103 or 105 disposed under the metal wiringlayer MTL or between the metal wiring layer MTL and the base substrate101, and a portion of the upper surface of the insulating layer 102, 103or 105 disposed in the non-display area NDA may be exposed. The metalwiring layer MTL is not necessarily disposed over the entire surface ofthe non-display area NDA, and may include patterns partially spacedapart from each other. A portion of the upper surface of the insulatinglayer 102, 103 or 105 disposed in the non-display area NDA may beexposed in a region where the patterns of the metal wiring layer MTL arespaced apart. Although it is illustrated in the drawing that, forsimplicity of description, the metal wiring layer MTL has patternsextending in one direction and spaced apart from each other in the otherdirection, or patterns having an inclined side surface, the invention isnot limited thereto. When the metal wiring layer MTL disposed on thedisplay panel 100 of the display device 10 has patterns partially spacedapart from each other, the shape thereof is not particularly limited.

In an embodiment, the sealing member 700 disposed in the non-displayarea NDA may be disposed on the metal wiring layer MTL and the exposedinsulating layer 102, 103 or 105, and at least a portion of the lowersurface of the sealing member 700 may be in direct contact with themetal wiring layer MTL and the exposed insulating layer 102, 103 or 105.The sealing member 700 may further include a fifth boundary surface CS5provided with the exposed insulating layer 102, 103 or 105 of thedisplay panel 100, in addition to the first boundary surface (CS1 inFIG. 9) provided with the metal wiring layer MTL. The fifth boundarysurface CS5 may be a portion where a physical boundary exists similarlyto the first boundary surface CS1, and the lower surface of the sealingmember 700 may be in direct contact with a portion of the insulatinglayer 102, 103 or 105 disposed on the display panel 100 in addition tothe metal wiring layer MTL.

As described above, the fusion region MA provided at the boundarybetween the sealing member 700 and the encapsulation substrate 500 maybe separated from the metal wiring layer MTL while overlapping the metalwiring layer MTL in the thickness direction. Although not illustrated,the non-display area NDA may include a portion in which the metal wiringlayer MTL is not disposed and the insulating layer 102, 103 or 105 isexposed, and the fusion region MA may overlap the exposed insulatinglayer 102, 103 or 105. That is, in some embodiments, the fusion regionMA may be provided between the sealing member 700 and the encapsulationsubstrate 500 so as not to overlap the metal wiring layer MTL in thethickness direction. Even when the second laser is irradiated, the metalwiring layer MTL may be prevented from being damaged.

In addition, since the display panel 100 includes a region in which themetal wiring layer MTL is not disposed in the non-display area NDA, thefusion region MA may be further disposed at a boundary between thesealing member 700 and the display panel 100.

FIG. 26 is a cross-sectional view illustrating a portion of a displaydevice in another embodiment. FIG. 27 is a cross-sectional viewpartially illustrating a process of fabricating the display device ofFIG. 26.

Referring to FIGS. 26 and 27, a display device 10_6 may further includea second fusion region MA2_6 provided between the sealing member 700 andthe display panel 100 in addition to a first fusion region MA1_6provided between the sealing member 700 and the encapsulation substrate500. The non-display area NDA of the display panel 100 may include aportion where the metal wiring layer MTL is not disposed and theinsulating layer 102, 103 or 105 is exposed, and the second fusionregion MA2_6 may be provided in the exposed portion of the insulatinglayer 102, 103 or 105. Since a description of the first fusion regionMA1_6 is the same as described above, the second fusion region MA2_6will be described in detail below.

The second fusion region MA2_6 may be provided at a portion of thenon-display area NDA of the display panel 100 where the metal wiringlayer MTL is not disposed and the insulating layer 102, 103 or 105 isexposed. The second fusion region MA2_6 may be provided over the sealingmember 700, the insulating layer 102, 103 or 105 of the display panel100, and the base substrate 101. The sealing member 700 may form a fifthboundary surface CS5, where a physical boundary exists, with a portionwhere the insulating layer 102, 103 or 105 is exposed. The second fusionregion MA2_6 may be a region where no physical boundary exists betweenthe sealing member 700 and the display panel 100, and a physicalboundary may not exist in a portion (NPA2 in FIG. 26) where the secondfusion region MA2_6 is disposed on the extension line of the fifthboundary surface CS5.

The fifth boundary surface CS5 may be provided between the sealingmember 700 and the exposed insulating layer 102, 103 or 105 of thedisplay panel 100. A sixth boundary surface CS6 may be provided betweenthe sealing member 700 and the second fusion region MA2_6. A seventhboundary surface CS7 may be provided between the second fusion regionMA2_6 and the base substrate 101 of the display panel 100. The fifthboundary surface CS5 may have a physical boundary. However, similarly tothe third boundary surface CS3 and the fourth boundary surface CS4, thesixth boundary surface CS6 and the seventh boundary surface CS7 may beboundaries where there are component differences according to positions,rather than physical boundaries. The second fusion region MA2_6 may be aregion in which components constituting the sealing member 700 andcomponents constituting the insulating layer 102, 103 or 105 of thedisplay panel 100 or the base substrate 101 are mixed. A detaileddescription thereof is substantially the same as described above withrespect to the first fusion region MA1_6.

In some embodiments, the second fusion region MA2_6 may include a thirdportion (e.g., upper portion of the second fusion region MA2_6 in FIGS.26 and 27) overlapping the sealing member 700 and a fourth portion(e.g., lower portion the second fusion region MA2_6 in FIGS. 26 and 27)overlapping the display panel 100, and the maximum value of the width W3of the third portion may be greater than the maximum value of the widthW4 of the fourth portion. As illustrated in FIG. 27, the second fusionregion MA2_6 may be provided by a second laser irradiated from the lowersurface of the base substrate 101 of the display panel 100. As describedabove, the second laser may be set such that its focal point isseparated from the lower surface of the base substrate 101, and an areato which the second laser is irradiated may be widened from the uppersurface of the base substrate 101 to the sealing member 700. In anembodiment, in the second fusion region MA2_6, the maximum value of thewidth W3 of the third portion may be greater than the maximum value ofthe width W4 of the fourth portion.

The display device 10_6 may further include the second fusion regionMA2_6 provided between the display panel 100 and the sealing member 700in addition to the first fusion region MA1_6 provided between theencapsulation substrate 500 and the sealing member 700. The sealingmember 700 includes the first fusion region MA1_6 separated from themetal wiring layer MTL while overlapping the metal wiring layer MTL inthe thickness direction and the second fusion region MA2_6 provided in aregion where the metal wiring layer MTL is not disposed. Accordingly,the bonding force between the sealing member 700 and the display panel100 and between the sealing member 700 the encapsulation substrate 500may be further improved.

In concluding the detailed description, those skilled in the art willappreciate that many variations and modifications may be made to thepreferred embodiments without substantially departing from theprinciples of the invention. Therefore, the disclosed preferredembodiments of the invention are used in a generic and descriptive senseonly and not for purposes of limitation.

What is claimed is:
 1. A display device comprising: a display panel including: a display area and a non-display area surrounding the display area; and a metal wiring layer disposed over at least a portion of the non-display area; an encapsulation substrate disposed on the display panel; a sealing member which is disposed between the display panel and the encapsulation substrate and bonds the display panel to the encapsulation substrate; and a first fusion region provided in at least a partial region between the sealing member and the encapsulation substrate, wherein at least a portion of the sealing member is disposed on the metal wiring layer in the non-display area, and the first fusion region is separated from the metal wiring layer while overlapping the metal wiring layer in a thickness direction.
 2. The display device of claim 1, wherein the first fusion region is provided by fusing a material of the sealing member with a material of the encapsulation substrate.
 3. The display device of claim 2, wherein a height of the first fusion region is greater than a thickness of the sealing member.
 4. The display device of claim 2, wherein the first fusion region includes a first portion positioned in parallel with the sealing member and a second portion positioned in parallel with the encapsulation substrate, and wherein a maximum value of a width of the first portion is greater than a maximum value of a width of the second portion.
 5. The display device of claim 4, wherein the sealing member forms a first boundary surface where at least a portion of a lower surface of the sealing member is in direct contact with the metal wiring layer, and the first boundary surface has a physical boundary with the metal wiring layer.
 6. The display device of claim 5, wherein the sealing member forms a second boundary surface where at least a portion of an upper surface of the sealing member is in direct contact with the encapsulation substrate, and the second boundary surface has a physical boundary with the encapsulation substrate, and wherein a physical boundary does not exist in a portion where the first fusion region is provided on an extension line of the second boundary surface.
 7. The display device of claim 4, wherein the first fusion region includes a third boundary surface between the first portion and the sealing member and a fourth boundary surface between the second portion and the encapsulation substrate.
 8. The display device of claim 4, wherein a thickness of the sealing member ranges from about 4.5 micrometers to about 6 micrometers, and a height of the first portion ranges from about 2 micrometers to about 4 micrometers.
 9. The display device of claim 2, wherein a plurality of first fusion regions is provided between the sealing member and the encapsulation substrate, and a width of the first fusion region is smaller than an interval between the plurality of first fusion regions.
 10. The display device of claim 9, wherein a maximum value of the width of the first fusion region ranges from about 8 micrometers to about 12 micrometers, and a maximum value of a height of the first fusion region ranges from about 8 micrometers to about 12 micrometers.
 11. The display device of claim 10, wherein the interval between the plurality of first fusion regions ranges from 50 micrometers to 100 micrometers.
 12. The display device of claim 1, wherein the display panel further includes an insulating layer disposed under the metal wiring layer, and wherein at least a portion of a lower surface of the sealing member is in direct contact with the insulating layer.
 13. The display device of claim 12, further comprising: a second fusion region provided between the sealing member and the insulating layer of the display panel, and, wherein the second fusion region is separated from the encapsulation substrate.
 14. The display device of claim 13, wherein the second fusion region includes a third portion positioned in parallel with the sealing member and a fourth portion positioned in parallel with the display panel, and wherein a maximum value of a width of the third portion is greater than a maximum value of a width of the fourth portion.
 15. The display device of claim 14, wherein the sealing member is in direct contact with the insulating layer of the display panel and includes a fifth boundary surface where a physical boundary exists, and wherein a physical boundary does not exist in a portion where the second fusion region is provided on an extension line of the fifth boundary surface.
 16. A display device comprising: a first substrate including a plurality of light emitting elements, the first substrate including a display area in which the plurality of light emitting elements is disposed and a non-display area surrounding the display area; a second substrate disposed on the first substrate; a metal wiring layer disposed in the non-display area of the first substrate; a sealing member which is disposed between the first substrate and the second substrate, overlaps the metal wiring layer and surrounds the display area in the non-display area; the sealing member including: a first extension portion extending in a first direction along the non-display area; a second extension portion extending in a second direction intersecting the first direction; and a first corner portion connected to the first extension portion and the second extension portion, the first corner portion having a curvature; and a fusion region provided between the second substrate and the sealing member, wherein the fusion region is provided at least in the first corner portion of the sealing member.
 17. The display device of claim 16, wherein the fusion region is also disposed in the first extension portion and the second extension portion of the sealing member, and wherein a plurality of fusion regions is spaced apart from each other in the first direction and the second direction.
 18. The display device of claim 17, wherein the fusion region forms a closed curve and surrounds the display area along the sealing member.
 19. The display device of claim 17, wherein a trench portion in which at least one of side surface is recessed inward is defined in the first substrate and the second substrate, and wherein the sealing member is disposed along an outer surface of the trench portion, and the fusion region is provided in the sealing member disposed corresponding to the outer surface of the trench portion.
 20. A method of fabricating a display device, the method comprising: preparing a first substrate including a display area and a non-display area and a second substrate facing the first substrate; bonding the first substrate to the second substrate via a sealing member; and irradiating an intense light to the sealing member to form a fusion region having no physical boundary at the interface between the second substrate and the sealing member.
 21. The method of claim 20, wherein a focal point of the intense light is set to be separated from an upper surface of the second substrate, and a separation distance between the focal point of the intense light and the upper surface of the second substrate ranges from about 0.1 micrometers to about 200 micrometers.
 22. The method of claim 21, wherein the intense light is irradiated at a frequency of about 1 kilohertz to 10 megahertz for about 10 femtoseconds to about 50 picoseconds.
 23. The method of claim 21, wherein the fusion region is disposed over the sealing member and the second substrate and separated from the first substrate.
 24. The method of claim 23, wherein the bonding the first substrate to the second substrate comprises filling frit crystals between the first substrate and the second substrate, and sintering and melting the frit crystals to form the sealing member. 